Programming Mecanums in Labview

[Hadi379]

This is our first year using Mecanum drive and we are having some trouble with programming these wheels in Labview. I realize there are a couple of threads discussing this topic, but I have some specifics I would like addressed. For instance:

1. Do you need one joystick or two to control the drive?
2. Can the holonomic vi be used for this drive system?
3. Are there any tutorials available that address this topic?
4. Any suggestions or tips?

Any information you could supply me with would be very helpful and appreciated. Thanks!

[Alan Anderson]

Originally Posted by Hadi379

This is our first year using Mecanum drive and we are having some trouble with programming these wheels in Labview. I realize there are a couple of threads discussing this topic, but I have some specifics I would like addressed. For instance:

1. Do you need one joystick or two to control the drive?
2. Can the holonomic vi be used for this drive system?
3. Are there any tutorials available that address this topic?
4. Any suggestions or tips?

1. You need three inputs to control forward/backward motion, left/right motion, and cw/ccw rotation. You can do that with as many or as few joysticks as you want, depending on the features the joysticks provide. We have typically used two joysticks configured exactly as we would for tank drive, along with the average of the X axes for sideways control.

2. The holonomic vi was written specifically for mecanum drivebases.

3. I don't know of tutorials, but there are a number of threads here on the Chief Delphi Forums that talk about how to do it. Try searching; if you still have specific questions, ask.

4. Listen to your drivers and try to make them happy.

[Hadi379]

Alan,

Well, as of right now, we are able to drive forward/backward, strafe in all directions off of joystick 1, BUT we have no CW/CCW rotation. I was attempting to get the rotation from joystick 2. I'd like to paste the code here if you would be willing to take a look at it, I feel like I'm making a simple wiring mistake.

Also, when we run the motors, the transmissions make a sound like their fighting themselves, kind of like a jittering motion. Is there anything I can do to refine the program?

Thanks for you time.

[Alan Anderson]

Originally Posted by Hadi379

Well, as of right now, we are able to drive forward/backward, strafe in all directions off of joystick 1, BUT we have no CW/CCW rotation...Also, when we run the motors, the transmissions make a sound like their fighting themselves, kind of like a jittering motion. Is there anything I can do to refine the program?

Before investigating software, this could be a simple mechanical issue. If you can't make your robot turn under its own power, you might have your wheels swapped.

Can you easily spin the robot by hand when its motors aren't running? If so, you definitely have your wheels swapped.

[Hadi379]

im pretty sure the wheels are arranged properly, plus, if they weren't, would I still be able to drive in the directions we've already achieved? We just can't get the robot to rotate cw/ccw.

[Chris is me]

Originally Posted by Hadi379

im pretty sure the wheels are arranged properly, plus, if they weren't, would I still be able to drive in the directions we've already achieved? We just can't get the robot to rotate cw/ccw.

Yeah, if your wheels are the wrong way, then you could still strafe and everything, just not spin.

[Hadi379]

Well, I'll have to double check them this weekend, but we arranged the wheels exactly how AndyMark recommends in their drawing...I'll let you know, but I really think it could be a programming problem...I'll post code later tonight if anyones willing to glance at it.